/*
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

/*
 * This file is available under and governed by the GNU General Public
 * License version 2 only, as published by the Free Software Foundation.
 * However, the following notice accompanied the original version of this
 * file:
 *
 * ASM: a very small and fast Java bytecode manipulation framework
 * Copyright (c) 2000-2011 INRIA, France Telecom
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the copyright holders nor the names of its
 *    contributors may be used to endorse or promote products derived from
 *    this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
 * THE POSSIBILITY OF SUCH DAMAGE.
 */

package org.objectweb.asm;

import java.io.DataInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.regex.Pattern;

/**
 * Defines additional JVM opcodes, access flags and constants which are not part of the ASM public
 * API.
 *
 * @see <a href="https://docs.oracle.com/javase/specs/jvms/se11/html/jvms-6.html">JVMS 6</a>
 * @author Eric Bruneton
 */
final class Constants {

    // The ClassFile attribute names, in the order they are defined in
    // https://docs.oracle.com/javase/specs/jvms/se11/html/jvms-4.html#jvms-4.7-300.

    static final String CONSTANT_VALUE = "ConstantValue";
    static final String CODE = "Code";
    static final String STACK_MAP_TABLE = "StackMapTable";
    static final String EXCEPTIONS = "Exceptions";
    static final String INNER_CLASSES = "InnerClasses";
    static final String ENCLOSING_METHOD = "EnclosingMethod";
    static final String SYNTHETIC = "Synthetic";
    static final String SIGNATURE = "Signature";
    static final String SOURCE_FILE = "SourceFile";
    static final String SOURCE_DEBUG_EXTENSION = "SourceDebugExtension";
    static final String LINE_NUMBER_TABLE = "LineNumberTable";
    static final String LOCAL_VARIABLE_TABLE = "LocalVariableTable";
    static final String LOCAL_VARIABLE_TYPE_TABLE = "LocalVariableTypeTable";
    static final String DEPRECATED = "Deprecated";
    static final String RUNTIME_VISIBLE_ANNOTATIONS = "RuntimeVisibleAnnotations";
    static final String RUNTIME_INVISIBLE_ANNOTATIONS = "RuntimeInvisibleAnnotations";
    static final String RUNTIME_VISIBLE_PARAMETER_ANNOTATIONS = "RuntimeVisibleParameterAnnotations";
    static final String RUNTIME_INVISIBLE_PARAMETER_ANNOTATIONS =
            "RuntimeInvisibleParameterAnnotations";
    static final String RUNTIME_VISIBLE_TYPE_ANNOTATIONS = "RuntimeVisibleTypeAnnotations";
    static final String RUNTIME_INVISIBLE_TYPE_ANNOTATIONS = "RuntimeInvisibleTypeAnnotations";
    static final String ANNOTATION_DEFAULT = "AnnotationDefault";
    static final String BOOTSTRAP_METHODS = "BootstrapMethods";
    static final String METHOD_PARAMETERS = "MethodParameters";
    static final String MODULE = "Module";
    static final String MODULE_PACKAGES = "ModulePackages";
    static final String MODULE_MAIN_CLASS = "ModuleMainClass";
    static final String NEST_HOST = "NestHost";
    static final String NEST_MEMBERS = "NestMembers";
    static final String PERMITTED_SUBCLASSES = "PermittedSubclasses";
    static final String RECORD = "Record";

    // ASM specific access flags.
    // WARNING: the 16 least significant bits must NOT be used, to avoid conflicts with standard
    // access flags, and also to make sure that these flags are automatically filtered out when
    // written in class files (because access flags are stored using 16 bits only).

    static final int ACC_CONSTRUCTOR = 0x40000; // method access flag.

    // ASM specific stack map frame types, used in {@link ClassVisitor#visitFrame}.

    /**
      * A frame inserted between already existing frames. This internal stack map frame type (in
      * addition to the ones declared in {@link Opcodes}) can only be used if the frame content can be
      * computed from the previous existing frame and from the instructions between this existing frame
      * and the inserted one, without any knowledge of the type hierarchy. This kind of frame is only
      * used when an unconditional jump is inserted in a method while expanding an ASM specific
      * instruction. Keep in sync with Opcodes.java.
      */
    static final int F_INSERT = 256;

    // The JVM opcode values which are not part of the ASM public API.
    // See https://docs.oracle.com/javase/specs/jvms/se9/html/jvms-6.html.

    static final int LDC_W = 19;
    static final int LDC2_W = 20;
    static final int ILOAD_0 = 26;
    static final int ILOAD_1 = 27;
    static final int ILOAD_2 = 28;
    static final int ILOAD_3 = 29;
    static final int LLOAD_0 = 30;
    static final int LLOAD_1 = 31;
    static final int LLOAD_2 = 32;
    static final int LLOAD_3 = 33;
    static final int FLOAD_0 = 34;
    static final int FLOAD_1 = 35;
    static final int FLOAD_2 = 36;
    static final int FLOAD_3 = 37;
    static final int DLOAD_0 = 38;
    static final int DLOAD_1 = 39;
    static final int DLOAD_2 = 40;
    static final int DLOAD_3 = 41;
    static final int ALOAD_0 = 42;
    static final int ALOAD_1 = 43;
    static final int ALOAD_2 = 44;
    static final int ALOAD_3 = 45;
    static final int ISTORE_0 = 59;
    static final int ISTORE_1 = 60;
    static final int ISTORE_2 = 61;
    static final int ISTORE_3 = 62;
    static final int LSTORE_0 = 63;
    static final int LSTORE_1 = 64;
    static final int LSTORE_2 = 65;
    static final int LSTORE_3 = 66;
    static final int FSTORE_0 = 67;
    static final int FSTORE_1 = 68;
    static final int FSTORE_2 = 69;
    static final int FSTORE_3 = 70;
    static final int DSTORE_0 = 71;
    static final int DSTORE_1 = 72;
    static final int DSTORE_2 = 73;
    static final int DSTORE_3 = 74;
    static final int ASTORE_0 = 75;
    static final int ASTORE_1 = 76;
    static final int ASTORE_2 = 77;
    static final int ASTORE_3 = 78;
    static final int WIDE = 196;
    static final int GOTO_W = 200;
    static final int JSR_W = 201;

    // Constants to convert between normal and wide jump instructions.

    // The delta between the GOTO_W and JSR_W opcodes and GOTO and JUMP.
    static final int WIDE_JUMP_OPCODE_DELTA = GOTO_W - Opcodes.GOTO;

    // Constants to convert JVM opcodes to the equivalent ASM specific opcodes, and vice versa.

    // The delta between the ASM_IFEQ, ..., ASM_IF_ACMPNE, ASM_GOTO and ASM_JSR opcodes
    // and IFEQ, ..., IF_ACMPNE, GOTO and JSR.
    static final int ASM_OPCODE_DELTA = 49;

    // The delta between the ASM_IFNULL and ASM_IFNONNULL opcodes and IFNULL and IFNONNULL.
    static final int ASM_IFNULL_OPCODE_DELTA = 20;

    // ASM specific opcodes, used for long forward jump instructions.

    static final int ASM_IFEQ = Opcodes.IFEQ + ASM_OPCODE_DELTA;
    static final int ASM_IFNE = Opcodes.IFNE + ASM_OPCODE_DELTA;
    static final int ASM_IFLT = Opcodes.IFLT + ASM_OPCODE_DELTA;
    static final int ASM_IFGE = Opcodes.IFGE + ASM_OPCODE_DELTA;
    static final int ASM_IFGT = Opcodes.IFGT + ASM_OPCODE_DELTA;
    static final int ASM_IFLE = Opcodes.IFLE + ASM_OPCODE_DELTA;
    static final int ASM_IF_ICMPEQ = Opcodes.IF_ICMPEQ + ASM_OPCODE_DELTA;
    static final int ASM_IF_ICMPNE = Opcodes.IF_ICMPNE + ASM_OPCODE_DELTA;
    static final int ASM_IF_ICMPLT = Opcodes.IF_ICMPLT + ASM_OPCODE_DELTA;
    static final int ASM_IF_ICMPGE = Opcodes.IF_ICMPGE + ASM_OPCODE_DELTA;
    static final int ASM_IF_ICMPGT = Opcodes.IF_ICMPGT + ASM_OPCODE_DELTA;
    static final int ASM_IF_ICMPLE = Opcodes.IF_ICMPLE + ASM_OPCODE_DELTA;
    static final int ASM_IF_ACMPEQ = Opcodes.IF_ACMPEQ + ASM_OPCODE_DELTA;
    static final int ASM_IF_ACMPNE = Opcodes.IF_ACMPNE + ASM_OPCODE_DELTA;
    static final int ASM_GOTO = Opcodes.GOTO + ASM_OPCODE_DELTA;
    static final int ASM_JSR = Opcodes.JSR + ASM_OPCODE_DELTA;
    static final int ASM_IFNULL = Opcodes.IFNULL + ASM_IFNULL_OPCODE_DELTA;
    static final int ASM_IFNONNULL = Opcodes.IFNONNULL + ASM_IFNULL_OPCODE_DELTA;
    static final int ASM_GOTO_W = 220;

    private Constants() {}

    static void checkAsmExperimental(final Object caller) {
        Class<?> callerClass = caller.getClass();
        String internalName = callerClass.getName().replace('.', '/');
        if (!isWhitelisted(internalName)) {
            checkIsPreview(callerClass.getClassLoader().getResourceAsStream(internalName + ".class"));
        }
    }

    static boolean isWhitelisted(final String internalName) {
        if (!internalName.startsWith("jdk/internal/org/objectweb/asm/")) {
            return false;
        }
        String member = "(Annotation|Class|Field|Method|Module|RecordComponent|Signature)";
        return internalName.contains("Test$")
                || Pattern.matches(
                        "jdk/internal/org/objectweb/asm/util/Trace" + member + "Visitor(\\$.*)?", internalName)
                || Pattern.matches(
                        "jdk/internal/org/objectweb/asm/util/Check" + member + "Adapter(\\$.*)?", internalName);
    }

    static void checkIsPreview(final InputStream classInputStream) {
        if (classInputStream == null) {
            throw new IllegalStateException("Bytecode not available, can't check class version");
        }
        int minorVersion;
        try (DataInputStream callerClassStream = new DataInputStream(classInputStream); ) {
            callerClassStream.readInt();
            minorVersion = callerClassStream.readUnsignedShort();
        } catch (IOException ioe) {
            throw new IllegalStateException("I/O error, can't check class version", ioe);
        }
        if (minorVersion != 0xFFFF) {
            throw new IllegalStateException(
                    "ASM9_EXPERIMENTAL can only be used by classes compiled with --enable-preview");
        }
    }
}
